The hermetic compressors for these cooling systems have their shells defining a hermetic chamber to be pressurized by an inert gas, such as nitrogen, and plugged in such a way as to prevent humidity from entering and consequently rusting the components located inside the hermetic chamber during the transport and warehousing of these compressors. Said pressurization is carried out through a gas feeding conduit, generally of a short length, attached to the hermetic shell so as to allow fluid communication between the interior and exterior of the chamber.
Before the inert gas is introduced into the interior of the hermetic shell, an open and of the gas feeding conduit is sealingly closed with an elastomeric element in the form of a plug, which is fitted under pressure and which is later perforated with a reduced diameter needle used to inject gas through the gas feeding conduit.
Although the needles have a small diameter, after they are removed at the end of the pressurizing operation of the shell, the plug remains with its structure broken, allowing the occurrence of small leaks of the gas introduced into the shell (close to 50 PPM). Besides this deficiency, this process of introducing gas into hermetic systems has the disadvantage of being a manual process, thus slow and subject to error.